Passenger aircraft currently in use conventionally comprise an aircraft fuselage comprising a load-bearing aircraft structure, to the outside of which an aircraft skin is fastened. In the region of the passenger cabin appropriate trim elements, such as for example side panels, roof panels, door panels etc., are mounted with clearance relative to the aircraft skin on an inner side of the aircraft structure. The cabin trim elements may be made for example from a glass-fibre reinforced plastic sandwich material, An intermediate space provided between the aircraft skin and the cabin trim elements is used to accommodate insulating elements, which are used to insulate the passenger cabin, particularly while the aircraft is in flight, from the low ambient temperatures and from noise emissions caused for example by the aircraft engines. The insulating elements are conventionally made of glass wool enclosed in a plastic foil.
The known insulating elements make it possible to realize the required beat-insulating and sound-insulating properties. However, an aircraft fuselage structure comprising an aircraft skin, cabin trim elements disposed with clearance relative to the aircraft skin, and an insulating layer disposed between these components does have the drawback that the insulating layer takes up a relatively large amount of room and also increases the weight of the aircraft. Fitting the insulating elements is moreover a very costly operation. Finally, an accumulation of condensation water in the insulating elements that occurs while the aircraft is in flight and is avoidable usually only with difficulty results in an undesirable weight increase and can occasionally lead to corrosion damage. For this reason, if moisture accumulations in the insulating elements are detected, this entails costly drying or exchange of the insulating elements.
To eliminate these drawbacks, new concepts for the design of an aircraft fuselage are currently being developed For example, DE 101 54 063 A1 describes a primary structural element, which may be used in aircraft construction and comprises an inner and an outer top layer of aluminium or a fibre composite material as well as a core element in the form of a folded honeycomb structure that is disposed between the two top layers. According to DE 101 54 063 A1 an air stream flowing through the core element can be utilized to remove moisture from the core element and feed it to a moisture management device.
If however the air stream flowing through the core element is itself not very dry, the air stream flowing through the core element may also introduce moisture into the primary structural element. However, the accumulation of moisture between the top layers in the region of the core element, in a similar manner to moisture accumulation in the insulating layer of a conventional aircraft fuselage arrangement, leads to an. undesirable increase of the weight of the primary structural element and may result in damage caused by corrosion or ice formation. To prevent the introduction of moisture into the intermediate space between the two top layers of the primary structural element, an air stream used to ventilate the core element may be dried before being fed into the core element. Drying of the air stream used to ventilate the core element however entails an extra outlay for equipment and increases both the energy demand and the weight of the system.
The object underlying the present invention is to provide a twin-shell aircraft fuselage elements with which in a simple and convenient manner it is possible to prevent harmful accumulations of water in the interior of the aircraft fuselage element.